Ein einfacher Weg zu 3′-Desoxy-α-L- und 3′-Desoxy-β-D-apionucleosiden

A Convenient Route to 3′-Deoxy-α-L- and 3′-Deoxy-β-D-apionucleosides The cyclic thionocarbonate 3, easily available in three steps from 3′-O-benzoyl-2,3-O-isopropylidene-D-apio-β-D-furanose (1), is deoxygenated with n-Bu3SnH to yield the 3′-deoxy epimers 4 [methyl 3-C-(benzoyloxymethyl)-3-deoxy-α-L-threo-tetrofuranoside] and 6 [methyl 3-C-(benzoyloxymethyl)-3-deoxy-β-D-erythro-tetrofuranoside]. These are separated by chromatography and further converted to the 3′-deoxy-α-L-apionucleosides 11–13, and the 3′-deoxy-β-D-apionucleosides 17–19, respectively.